﻿<html>
<head>
   <meta charset="utf-8">
   <title>tyg</title>
   <style type="text/css">
   .top{
        height:54px;
        width:100%;
        position:absolute;
        top:0;
        left:0;
        backgrund:rgba(255,0,0,0，5)；
       }
   </style>
</head>
<body>
<p>置于透明下面的文字</p>
<div class="top"></div>
</body>
</html>